APPLICATIONS - VALVE SEAT/SEAL MATERIALS
One of the most important factors affecting shutoff capability is the nature of media being handled. Service life is affected by all
of the following factors: - pressure, temperature, degree of pressure fl uctuation and thermal fl uctuation, type of media, cycling
frequency, velocity of media & speed of valve operation.
The following seat & seal materials can be used in various valves such as ball, plug, butterfl y, needle, etc.
BUNA-N (HYCAR or Nitrile) - Buna-N is a general-purpose polymer which has good resistance to oil, water, solvents and hydraulic
fl uids. It also displays good compression, abrasion resistance, and tensile strength. This material performs extremely well in process
areas where paraffi n base materials, fatty acids, oils, alcohols or glycerins are present, since it is totally unaffected. It should not be
used around high polar solvents (acetones, ketones), chlorinated hydrocarbons, ozone or nitro hydrocarbons. Temperature range
is 107°C maximum. Hycar is black in colour and should not be used where discolouration cannot be tolerated. It is regarded as a
comparable replacement neoprene. Major differences are: Buna-N has a higher temperature limit; neoprene is more resistant to oils.
CARBON FILLED TFE - Carbon fi lled TFE is an excellent seat material for steam applications as well as high effi ciency oil-based
thermal fl uids. Fillers including graphite enable this seat material to have a better cycle life than other fi lled or reinforced TFE seats.
Temperature range is -29°C to 260°C. Chemical resistance is equal to other TFE seats.
EPDM - EPDM is a terpolymer elastomer made from ethylene-propylene diene monomer. EPDM has good abrasion and tear resistance
and offers excellent chemical resistance to a variety of acids and alkalines. It is susceptible to attacks by oils and is not recommended
for applications involving petroleum oils, strong acids, or strong alkalines. EPDM should not be used on compressed air lines. It has
exceptionally good weather aging and ozone resistance. Temperature rating is from -29°C to 107°C (121°C intermittent service). It is
fairly good for ketones and alcohols.
HYPALON® - Hypalon has very good resistance to oxidation, ozone and good fl ame resistance. It is similar to neoprene except with
improved acid resistance where it will resist such oxidizing acids as nitric, hydrofl ouoric and sulfuric acid. Abrasion resistance of
Hypalon is excellent, about the equivalent of the nitriles. Oil and solvent resistance is somewhat between that of neoprene and nitriles.
Salts have little if any effect on Hypalon. Hypalon is not recommended for exposure to concentrated oxidizing acids, esters, ketones,
chlorinated, aromatic and nitro hydrocarbons. Not to be used in steam service. Temperature rating is from -18°C to 104°C. Seats are
white food grade and may be used on food service as well as bleached paper lines.
NEOPRENE - Neoprene is an all-purpose polymer with many desirable characteristics. Neoprene features high resiliency with low
compression set fl ame resistance and animal and vegetable oil resistance. It is principally recommended for use in pulp and paper
applications. Generally, neoprene is not recommended and is attacked by strong oxidizing acids, most chlorinated solvents, esters,
ketones, aromatic hydrocarbons and hydraulic fl uids. Neoprene is not generally affected by moderate chemicals, fat, greases and many
oils and solvents. Temperature rating is from -29°C to 82°C. Seats are black in colour and should not be used on bleached paper lines.
PTFE (TFE of Tefl on®) - PTFE is the most chemically resistant of all plastics. It also has excellent thermal and electrical insulation
properties. PTFE’s mechanical properties are low compared to other engineering plastics, but its properties remain at useful levels over
a great temperature range (-40°C to 204°C, depending on brand and application).
RTFE (Reinforced TFE) - RTFE is compounded with a selected percentage of fi bre glass fi ller to improve strength and resistance
to abrasive wear, cold fl ow, and permeation in molded seats. Reinforcement permits application at higher pressure and temperature
than unfi lled TFE. Typical temperature range is -40°C to 232°C. RTFE should not be used in applications that attack glass, such as
hydrofl uoric acid and hot strong caustics.
TFM1600 - TFM1600 is a modifi ed version of PTFE that maintains the exceptional chemical and heat resistance properties of PTFE,
but has a signifi cantly lower melt viscosity. The result is reduced cold fl ow, porosity, permeability and void content. Surfaces are
smoother and reduce torques. The theoretical service range for TFM1600 is -200°C to 260°C.
TFM1600+20%GF - TFM1600+20%GF is a fi bre glass reinforced version of TFM1600. Similar to RTFE, but with the benefi t of
TFM1600, the glass fi lled version provides greater abrasion resistance and improves stability at higher pressures.
TFM4215 - TFM4215 is an elector graphitized carbon fi lled TFM material. The added carbon improves stability for higher pressure and
temperature combinations.
VITON® (Fluorocarbon, FKM, or FPM) - Fluorocarbon elastomers are inherently compatible with a broad spectrum of chemicals.
Because of this extensive chemical compatibility which spans considerable concentration and temperature ranges, fl uorocarbon
elastomers have gained wide acceptance as a material of construction for knife gate valve seats. Fluorocarbon can be used in
most applications involving mineral acids, salt solutions, chlorinated hydrocarbons and petroleum oils. It is particularly good in
hydrocarbon service. Temperature rating is from -29°C to 149°C. Colour is grey (black) or red and may be used on bleached paper
lines. Fluorocarbon (VITON) is not suitable for steam or hot water service, however, in o-ring form it can be acceptable for hydrocarbon
lines mixed with hot water depending on the type/brand. For seat materials FKM can offer more resistance to hot water - consult
manufacturer.
of the following factors: - pressure, temperature, degree of pressure fl uctuation and thermal fl uctuation, type of media, cycling
frequency, velocity of media & speed of valve operation.
The following seat & seal materials can be used in various valves such as ball, plug, butterfl y, needle, etc.
BUNA-N (HYCAR or Nitrile) - Buna-N is a general-purpose polymer which has good resistance to oil, water, solvents and hydraulic
fl uids. It also displays good compression, abrasion resistance, and tensile strength. This material performs extremely well in process
areas where paraffi n base materials, fatty acids, oils, alcohols or glycerins are present, since it is totally unaffected. It should not be
used around high polar solvents (acetones, ketones), chlorinated hydrocarbons, ozone or nitro hydrocarbons. Temperature range
is 107°C maximum. Hycar is black in colour and should not be used where discolouration cannot be tolerated. It is regarded as a
comparable replacement neoprene. Major differences are: Buna-N has a higher temperature limit; neoprene is more resistant to oils.
CARBON FILLED TFE - Carbon fi lled TFE is an excellent seat material for steam applications as well as high effi ciency oil-based
thermal fl uids. Fillers including graphite enable this seat material to have a better cycle life than other fi lled or reinforced TFE seats.
Temperature range is -29°C to 260°C. Chemical resistance is equal to other TFE seats.
EPDM - EPDM is a terpolymer elastomer made from ethylene-propylene diene monomer. EPDM has good abrasion and tear resistance
and offers excellent chemical resistance to a variety of acids and alkalines. It is susceptible to attacks by oils and is not recommended
for applications involving petroleum oils, strong acids, or strong alkalines. EPDM should not be used on compressed air lines. It has
exceptionally good weather aging and ozone resistance. Temperature rating is from -29°C to 107°C (121°C intermittent service). It is
fairly good for ketones and alcohols.
HYPALON® - Hypalon has very good resistance to oxidation, ozone and good fl ame resistance. It is similar to neoprene except with
improved acid resistance where it will resist such oxidizing acids as nitric, hydrofl ouoric and sulfuric acid. Abrasion resistance of
Hypalon is excellent, about the equivalent of the nitriles. Oil and solvent resistance is somewhat between that of neoprene and nitriles.
Salts have little if any effect on Hypalon. Hypalon is not recommended for exposure to concentrated oxidizing acids, esters, ketones,
chlorinated, aromatic and nitro hydrocarbons. Not to be used in steam service. Temperature rating is from -18°C to 104°C. Seats are
white food grade and may be used on food service as well as bleached paper lines.
NEOPRENE - Neoprene is an all-purpose polymer with many desirable characteristics. Neoprene features high resiliency with low
compression set fl ame resistance and animal and vegetable oil resistance. It is principally recommended for use in pulp and paper
applications. Generally, neoprene is not recommended and is attacked by strong oxidizing acids, most chlorinated solvents, esters,
ketones, aromatic hydrocarbons and hydraulic fl uids. Neoprene is not generally affected by moderate chemicals, fat, greases and many
oils and solvents. Temperature rating is from -29°C to 82°C. Seats are black in colour and should not be used on bleached paper lines.
PTFE (TFE of Tefl on®) - PTFE is the most chemically resistant of all plastics. It also has excellent thermal and electrical insulation
properties. PTFE’s mechanical properties are low compared to other engineering plastics, but its properties remain at useful levels over
a great temperature range (-40°C to 204°C, depending on brand and application).
RTFE (Reinforced TFE) - RTFE is compounded with a selected percentage of fi bre glass fi ller to improve strength and resistance
to abrasive wear, cold fl ow, and permeation in molded seats. Reinforcement permits application at higher pressure and temperature
than unfi lled TFE. Typical temperature range is -40°C to 232°C. RTFE should not be used in applications that attack glass, such as
hydrofl uoric acid and hot strong caustics.
TFM1600 - TFM1600 is a modifi ed version of PTFE that maintains the exceptional chemical and heat resistance properties of PTFE,
but has a signifi cantly lower melt viscosity. The result is reduced cold fl ow, porosity, permeability and void content. Surfaces are
smoother and reduce torques. The theoretical service range for TFM1600 is -200°C to 260°C.
TFM1600+20%GF - TFM1600+20%GF is a fi bre glass reinforced version of TFM1600. Similar to RTFE, but with the benefi t of
TFM1600, the glass fi lled version provides greater abrasion resistance and improves stability at higher pressures.
TFM4215 - TFM4215 is an elector graphitized carbon fi lled TFM material. The added carbon improves stability for higher pressure and
temperature combinations.
VITON® (Fluorocarbon, FKM, or FPM) - Fluorocarbon elastomers are inherently compatible with a broad spectrum of chemicals.
Because of this extensive chemical compatibility which spans considerable concentration and temperature ranges, fl uorocarbon
elastomers have gained wide acceptance as a material of construction for knife gate valve seats. Fluorocarbon can be used in
most applications involving mineral acids, salt solutions, chlorinated hydrocarbons and petroleum oils. It is particularly good in
hydrocarbon service. Temperature rating is from -29°C to 149°C. Colour is grey (black) or red and may be used on bleached paper
lines. Fluorocarbon (VITON) is not suitable for steam or hot water service, however, in o-ring form it can be acceptable for hydrocarbon
lines mixed with hot water depending on the type/brand. For seat materials FKM can offer more resistance to hot water - consult
manufacturer.
